Electric heater.



W. S. HADAWAY, Jn. & E. N. LIGHTFOOT.

ELECTRIC HEATER.

APPLICATION Flu-:D FEB. 6. '1913.

Patented July 13, 1915.

INVENTORS,

UNITED STATES PATENT oEEIoE.

WILLIAM s. IIADAWAY, JE., or NEW ROCHELLE, AND EEWIN N. LIGHTEooT, 0E i NEW YoEK, N. Y.

ELECTRIC HEATER.

Specification of Letters Patent.

Patented July 13, 1915.

To all whom 'it may concern Be it' known that We, WILLIAM S. HABA- WAY, Jr., and EDWIN N. LIGnTFooT, citizens of the United States, residing, respectively, at New Rochelle, in the county of Westchester, and at New York, in the count of New York, both in the State of New ork,

have invented new and useful Improvements in Electric Heaters, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates to improvements in electric heaters.

Oneof the objects of the invention is to provide a heating unit which may be readily -applied to various electric heating appliances withoutmodifying the existing construction thereof.

Another object is to provide improved means forr securing an electrical resistance to the base kof electric appliances in such a4 manner asto localize the heat or confine it mainly to a small area.

.A further object is to provide an electric heater in the form of an attachment which,

' when applied to the device to be heated, is

neat, compact, unobtrusive and does not detract from the appearance of said device.

In. the accompanying drawings we have illustrated several forms of heaters which embody our invention. To aid in an understanding of said heaters we have shown them as constructed with'particular reference to their use in connection with coffee percolators, the latter being good examples of the class of utensils or appliances for which said yheaters are adapted.

The invention is not limited to the embodiments illustrated, nor to their use in connecl tion with percolators.

Figure 1 is a sectional elevation of a coffe percolator showing an electrical heating unit assembled as a permanent part thereof. Fig.

2 is a view on an enlarged scale showing the;

. electrical resistance and its adjuncts by which it is attached to and insulated from the base of the percolator, the adjacent parts being spaced apart to disclose the manner of assembling. Fig.. 3 is'a bottom, plan view of the resistor. Fig. 4 is a sectional elevation of a modified arrangement for securing the resistor to the base of the percolator. Fig. 5 is a further modification thereof.

Fig. G is an elevation of a modified termina-l mounting.

The coffee percolator 1 illustrated in the drawings is of standard design and it need n ot be specifically described except to state briefly that it comprises a lower receptacle 2 which initially contains water, an upper chamber 3, an intermediate coiee receptacle or tray 4, and a tube 5 passing through the base Aof the lower receptacle and communieating with a well 6 in the base plate or heating plate 7. Such bases have heretofore been heated by an alcohol lamp, whereupon steam forms in the well and some of the liquid is expelled through suitable openings 1n the top of the tube 5, and trickling through the coffee receptacle is returned to the lower chamber from which the liquid coffee is eventually drawn off. In order to heat said base plate'7 electrically and without modifying the construction of the percolator, we provide a suitable resistor or resistors 8 which in the present instance have the form of a wire wound spirally, the adjacent turns being separated by an asbestos string 9. The'resistors, of which there are preferably two separated by a layer of mica,

may, of course, assume various other forms,

. thereof. To minimize downward radiation of heat, we provide a non-conducting disk 13 which fits within said casing in the manner indicated. The relative arrangement of the parts is clearly shown in Fig. 2, said parts being held against the base by the bending in or spinning over of the upper part of the flange 11 as indicated in Fig. l. The resistors are thereby held very close to the lower surface of the heating plate 7, being separated therefrom only by a few thicknesses of mica. Accordingly most of the heat is transferred or communicated to the heating plate 7, and localized or concen- 50 i* modification, many of the elements ofywhich vare similar to those previously described,

trated about the well 6, downward radiation being cut off by the disk 13. The inwardlybent vflange 11 .firmly secures all the parts in position and rendersthe heatingunit as? `a whole a unitary part of the percolator.

Said unit is also water-tight. The desired pressure is applied to the resistors, the latl ter being also held in position by the carrier. f

The said heatingunit is comparatively thin and inconspicuous and in no way detracts from the appearance of the' deviceras a which are supported by the carrier `but insulated therefrom 4by mica washers 15 ar-` ranged on opposite sides of 'a horlzontal l1p whole. f

Suitable circuitv terminals 14 are provided housing having its upper end flanged outwardly and suitably secured to the carrier ne method of securing itis to electrically weld it thereto. A notch -19 in said housing insures the proper relative circuit connections when the necessary attachmentl plug is inserted therein. The terminals-are elevated sufficiently to permit ready attachment of a plug from beneath. If a ylow vstand is employed, isis preferable to attach Land detach the plugA by a movement vin a horizontal plane. An arrangement of hori'- zontal terminal pins is shown in Fig. 6 and hereinafter described.

In Fig.` 4, `we have illustrated a modified form 'of heater in which the carrier or disk 10 is secured by a separate. independent flange 11, the latter'being spun over both at the bottom and at the top. The remaining elements are the same as those previously described.

In Fig. 5, we have illustratedv a further i and accordingly the same reference characters have been 'applied to indicate corresponding parts. The base plate 20 in this case, however, is provided with a downwardly extending ange 21, within which is received a -cover plate 22, having screwthreaded engagement therewith. Said cover Vplate consists ofya sheet metal disk having fa central opening within which a tubular extension 24 is secured, preferably by weld- `ing'it thereto to form a unitary'v device. The vlower end of said extension is flanged inwardly to support the terminal members bled.

In' Fig. 6, we have illustrated 'a construcjj i Ytion permitting a horizontal arrangement of lwhich are secured thereto in a manner similar to that previously described. An additional inclosing casing25 is provided having Y 'i a contracted upper portion which fits over said extension 24 and is suitably secured 1n position yafter -the parts have been assegnthe terminal pinsthereby permitting the body of theutensil to be mounted on a lower base. The carrier 10 is provided preferably with radial reinforcing ribs 26 struck therefrom. Arectangular metallic tube 27 is supported centrally from said disk and is so..v

cutaway diagonally, the opening being closed by the plate 28. formed on oneside of said tube, on the oppo- A flange' 29 is 'i i site side of which liange mica washers are.

arranged in the manner previously de-f scribed, saidwashers supporting the termi- 'nal pins 14 in a horlzontal position.V

In the various forms of device previously described itis desirable in most cases 'to have the resistance element made up of two spiral resistors'such as shown in Fig. 3,-and a to provide three terminal'pins. The inner ends of`both coils are connected to one ter-` minal pin and the outer ends thereof are connectedk to the other two terminal pins.

by using either resistor, separately. y nectmg both resistors in parallel a third heat is obtained. The chan e in circuit connecs The resistors are of unequal resistance*y f V'whereby two different heats maybe obtained By contions is eiected by a suitable controller, not@k shown. 1J*

It is to be understood, of course, that the invention is not to be limited to the several formsl thereof illustrated and descrbed, as

which fall within the scope of the claims. f What we claim as new and desire to secure by Letters Patent is:

1. In an electrical heatingdevice, a base annular flange conforming to the contour of Vsaid base plate, saidl annular flange bein bent over the outer upper vsurface of sai ,iilpsfE base plate to secure said resistance in close thermal contact with said base plate.

2. In combination, a heating late havmg'z* ay central Well for the liquid to y resistance for heating said base plate, a

heated, a

metallic` carrier for said.. resistance, and

means for insulating said resistance from said `base plate and from .said carrier, the

latter having means flanged over said `basev plate to hold said carrier and said lresistance firmly against said base plate.

3. In combination, a heating disk having Y' n a central supportin boss with anopening therein for the liquld to be heated, a cupshaped sheet metal carrier having a flange y rosA various other embodiments may be devised 1 l 110 i plate, a resistance adjacentto the undersur'- vface thereof, a sheet metal carrier having an' f f within which said disk is received, the upper margin of said flange being bent over said disk to lock the parts together, a resistance arranged between said carrier and said disk, insulation on opposite sides of said resistance, and heat insulating material between said resistance and said carrier.

4. The combination with a liquid receptacle having a base with an opening therein,

of a heating plate therefor, said plate being secured to said base and having anopening registering with the opening in said base, an electrical 'resistance in the form of a thin, fiat element arranged beneath said plate, and terminal members arranged beneath said resistancev and supported by said plate.

5. The combination with a heating disk for liquids, of means for supporting said disk at an intermediate portion of its upper surface thereby leaving a free outer margin, flat resistance coils arranged against the under surface of said disk, means for preventing downward radiation of heat from said coils, and means depending from said outer margin for securing said coils in close heat conduction relation with said disk.

6. The combination with a heating diskl `for liquids, of means for supporting said under surface of said disk, an annular flange depending from said outer margin, a plate connected to the lower end of said flange to form with said base, an inclosure for said resistance coils, circuit terminals supported by said plate, and connections from said circuit terminals t'o said coils to permit connection thereof either in series or parallel.

7. A resistance carrier for a percolator comprising a cup-shaped element having a central opening and a cylindrical element concentric with said opening and integrally united to said carrier.

8. A resistance carrier for a heating device comprising a metallic plate having a peripheral fiange for securing said plate to the object to be heated, said plate having a central opening, circuit terminals arranged in said opening and supported by said plate but out of contact electrical therewith, and a metallic housing secured to said plate and surrounding said terminals.

' In witness whereof, we have hereunto subscribed our names in the presence of two witnesses.

WILLIAM S. HADAWAY, J R. EDWIN N. LIGHTFOOT.

Witnesses:

GEORGE J. MALLON, G. P. BRocKwAY. 

